1. Field of the Invention
This invention relates to a pesticidal composition comprising S-methyl N-(methylcarbamoyloxy)thioacetamidate and certain .alpha.-cyanobenzyl phenylacetates.
2. Description of the Prior Art
Certain cyclopropane carboxylic acid derivatives are a useful class of pesticides called "pyrethroids" which have been of considerable interest because of their quick knockdown activity, low persistence as toxic residues and their low mammalian toxicity. Certain derivatives of phenylacetic acids have also been found to have properties of the pyrethroid type. Unfortunately, while such compounds are desirable pesticides, they tend to be difficult or expensive to manufacture due to their relatively complex chemical structures.
U.S. Pat. No. 3,835,176 discloses insecticidal compositions containing certain carbamates with certain .alpha.-cyanobenzyl cyclopropane-carboxylate.
Applicants have found that combinations of certain .alpha.-cyanobenzyl phenylacetate pyrethroids with S-methyl N-(methylcarbamoyloxy)thioacetamidate as hereinafter described possess synergistic activity with respect to acarid pests, that is to say the activity of the combination of the two pesticides produces a more-than-additive pesticidal effect.